High Alcohol Intake Harms Sperm Quality

The more alcohol young men drink, the lower their sperm count and quality may be, according to a study published in BMJ Open. In addition, high alcohol consumption was linked to a higher risk of contracting human papillomavirus (HPV), according to a study published in Sexually Transmitted Infections.

The first study involved 1,221 Danish men between the ages of 18 and 28. They filled out questionnaires about their drinking, provided a semen sample, and had their blood drawn. The researchers found that sperm concentration, total sperm count, and percentage of normal sperm were all poorer among men having at least five units of alcohol a week.

The amount of testosterone measured in the men's blood, however, increased as their alcohol intake increased. The drop in sperm count and quality became particularly significant among men consuming at least 25 units of alcohol a week. Those drinking 40 or more units a week had a 33 percent lower sperm concentration than those consuming one to five units a week.

The second study included 1,313 American men. The researchers found that those who drank the most alcohol (more than 10 grams a day) were 13 percent more likely to have any HPV type and 35 percent more likely to have a cancer-related HPV type, compared to those drinking the least amount of alcohol (less than 0.1 gram per day).

Even after the researchers took into account the number of sex partners the men had and whether they smoked -- another risk factor for HPV-associated cancers -- the study still found an link between alcohol consumption and HPV infection.

"Many men are quiet drinkers who don't realize that this may affect them as they drink a lot more than they admit to," Michael Heard, M.D., an obstetrician-gynecologist and reproductive endocrinologist at The Heard Clinic and Houston Methodist Hospital told HealthDay.